Climate change and the global public health community Preoccupied by the opportunity to make significant inroads into infectious disease

prevention and control, the global health community was slow to respond to the rise of climate change on the political agenda.⁸ However, building on the pioneering work of Tony McMichael and others,^9–12 in 2008 the World Health Assembly rec-ognized climate change as one of the defining health challenges of the 21st century, and protecting health from its impacts as a priority for the public health community.

It is now well understood that the impacts of climate change on global health and development are manifold.¹³ They result from changes in the extent and distri-bution of global warming (of the atmosphere and oceans); the changes in amount and variability of rainfall; the increased frequency and magnitude of extreme weather events and the extent and distribution of sea-level rise. Elevation of CO₂ in the atmosphere affects plant production, nutritional content and allergens as well as acidification of the oceans. In addition, society’s response to climate change, in terms of both mitigation and adaptation, may of itself result in health impacts.

Climate change is substantially caused by increases in GHG emissions that are associated with the release of carbon from fossil fuel consumption. Rapid ‘decar-bonization’ of society is key to climate change mitigation. The health benefits of reduced air pollution provide a powerful additional argument for the immedi-ate economic and social benefits of reductions in carbon emissions at both the local and global level.¹³ Consequently, health is now identified as a critical priority for protection from climate change as well as a co-benefit of mitigation in the United Nations Framework Convention on Climate Change (UNFCCC) Paris Climate Agreement of 2015. This accord committed countries to lowering GHG emissions in order to restrain warming below 2^oC. However, in 2016 the United States decided to back away from the Paris Accord.¹⁴ Despite this, economically powerful States, such as New York and California, continue to strengthen their cli-mate change mitigation and adaptation activities. Paris reinforced the need for both developing and developed countries to create National Adaptation Plans (NAPs) to drive their adaptation agenda. Countries are currently developing NAPs; some of which include health as a priority.

1.3.1 Climate impacts on infectious diseases

Pressure to act on climate change is increasing in part because changes in the climate (and associated floods, droughts, heatwaves) are already being observed in many regions of the world.¹⁵ These are associated with a range of health impacts.

For example, an increased risk of respiratory, diarrheal, vector-borne and soft- tissue infectious diseases is observed amongst flood survivors and responders.¹⁶ Many infectious diseases are climate-sensitive; climate acting as an important driver of spatial and seasonal patterns of infections, year-to-year variations in incidence (including epidemics), and longer-term shifts in populations at risk.¹⁷ Increasingly those responsible for the development of disease control strategies have identified

climate change as a challenge to their activities and climate information as a poten-tial resource for programme planning.¹⁸

1.3.2 Climate impacts and disaster risk reduction

Epidemics and pandemics of air, water and vector-borne (i.e., transmitted by insects, ticks and snails) diseases may be identified as disasters in their own right; they have recently been included in the global institutional processes for disaster risk reduc-tion (DRR).

A recent report¹⁹ analysing trends in the past 20 years shows that 90% of disasters are weather-related with floods accounting for 47% of all hydro-meteorological disasters. These disasters claimed more than 600,000 lives, with an additional four billion or more people injured, left homeless or in need of emergency assistance. The report also noted that Africa is more affected by drought than any other continent.

Both climate and health shocks can have short term and long term (including intergenerational) impacts as evidenced from detailed household studies in Ethiopia.²⁰ The impacts of such disasters are experienced disproportionally by the poor²¹ and mounting an effective response requires effective collaboration between health and DRR communities. The Sendai Framework for Disaster Risk Reduc-tion 2015–2030²² recognizes health as a key element of DRR and places emphasis on building resilient health systems through integration of all-hazards disaster risk management within health care and public health provision. This is a major advance on prior DRR frameworks which substantially ignored the role of the health sector in disaster response. Although civil defence agencies and non-governmental actors tend to dominate the disaster response community the health sector is needed to co- ordinate and promote health activities. This is most effective when it is undertaken with a people-centred approach. Whilst there is an urgent need to advance DRR initiatives in health, it is important to systematically integrate health care initiatives within DRR efforts to create a more comprehensive approach.

To advance the Sendai Framework for Disaster Risk Reduction and to bring the health and DRR communities together the Royal Thai Government, UN Office for Disaster Risk Reduction and the WHO organized an international conference on 10–11 March 2016, in Bangkok, Thailand. The conference report ‘The Bangkok Principles’ⁱ offers opportunities for collaboration between all relevant sectors and stakeholders who wish to integrate health in DRR plans and strategies.ⁱⁱ Further-more, ‘The Bangkok Principles’ fosters the inclusion of emergency and disaster risk management (DRM) programmes in health policies and strategies. Collaborative work between health and DRR communities now focuses on understanding disas-ter risk in all its dimensions of exposure, vulnerability and capacity. Joint risk assess-ment, profiling and prioritization as well as integrating health data into disaster loss databases is a vital part of this process, leading to comprehensive risk mitigation and reduction strategies.

Whilst climate change is moving up the health and DRR agendas the practical responses to climate shocks vary; reflecting the differences in community actors

and institutional priorities. These differences are well illustrated if we consider the impacts of a major drought. Immediate practical responses to the drought may come from the agricultural or development community focused on household live-lihoods, or through a national or local insurance scheme which provides resources to affected households based on agreed triggers such as those used for weather index insurance.²³

1.3.3 Climate impacts on nutrition

Nutritious and sufficient food is the basis of health. Droughts can have a major impact on the nutritional status of vulnerable populations, particularly children, the elderly and women. These impacts, which may be the result of low calorie intake, insufficient micro-nutrients or infectious diseases such as diarrhoea, respira-tory infections and parasites, have immediate and life-long effects.²⁴ Undernutrition persists in many countries but recently being overweight and/or obese has become an equally, if not more, important issue for health. This reflects an extraordinary transformation of global food systems especially in low and middle-income coun-tries (LMICs). This transformation is largely determined by rising incomes, urban-ization and greater economic activity in food systems in relation to processing, logistics and food retail. As a consequence, per capita consumption of meat, fish, vegetable, sugar and fats is increasing. This dietary transition has reduced calorie and micro-nutrient deficiency on the one hand, but dramatically increased obesity and associated non-communicable diseases (NCDs) on the other.²⁵ It is estimated that 50% of disease mortality and disability is now associated with NCDs such as cardiovascular disease and diabetes.²⁶ The impact of this transition is greatest in LMICs with enormous implications for health systems development. Health costs as a percentage of Gross Domestic Product (GDP) are typically 1 to 4% in low and lower-middle income countries. Pacific Island countries, with very high rates of obesity and NCDs, have health costs from 10–15% of GDP²⁷ mirroring what is observed in wealthier nations. The nutrition challenge is currently being addressed in the Decade for Action of Nutrition following the 2^nd International Conference on Nutrition (ICN2).²⁸ Given the lack of past success in public campaigns to slow the increase in obesity and prevalence of NCDs, targets are usually very modest and often limited to a focus on children.^26,29

1.3.4 Impact of food systems on climate and health

Crop production and supply chains that form the basis of food systems are impacted directly by climate. They are also major contributors to the GHG emissions that are the cause of human-induced (anthropogenic) climate change. Depending on the estimation method, from 20 to 30% of all GHG emissions come from food systems and this is even more significant in LMICs.^30,31 Thus, while food production, pro-cessing, transport and consumption must adapt to a changing climate, creating a low carbon food system that minimizes its exploitation of water and land is a critical

part of any country’s climate mitigation strategy. The nutrition community has been slow to engage with climate adaptation; the 2015 Global Nutrition Report³² reported that, of those surveyed, only a small proportion of country nutrition plans made mention of climate related risks.

Likewise, the health sector has been surprisingly slow to get involved in nutrition and food issues in part because it requires broad engagement with the food indus-try. This needs to change given the rapidly increasing importance of private sector activities to both health and planetary sustainability.³³ Nutrition and food system issues will require a multi-sectoral approach with polices and investments recogniz-ing the trade-offs of benefits and costs to different sectors (health, socio-economic, agri-food, environment). There is a need for policy levers that help focus the food industry on healthy diets and a safe and sustainable ‘climate smart’ food system for all.³⁴ Major investments in efficiency and effectiveness have the potential to reduce environmental costs, including climate related risks, while ensuring healthier foods (vegetables, legumes/pulses, fish, milk) at lower prices, especially for poor people and their children. Combined actions of both public and private sectors will be essential for progress in improving the sustainability and health of food systems.

1.3.5 From MDGs to SDGs

The Sustainable Development Goals (SDGs) (Box 1.1) provide a new paradigm in global health and development with their focus on new institutional relationships at the country level. This is particularly important for the health sector given that many of the drivers of health outcomes are the responsibilities of line ministries (e.g., transport, energy, agriculture), other institutions (including from the private sector) and communities that are not from within the formal health sector. From MDGs to SDGs there is increasing congruence between health, disaster risk reduc-tion, nutrition and climate change policy processes.

1.3.6 Universal Health Coverage

Operationalization of the SDGs’ health aspirations is being sought through imple-mentation of programmes that support Universal Health Coverage (UHC). This initiative seeks to ensure that all people and communities can use effective, pro-motive, preventive, curative, rehabilitative and palliative health services that they need within manageable costs³⁵ although the detailed financing mechanisms needed remain to be established. Historically the health community has had lit-tle engagement and support from the major climate mitigation and adaptation funds. However, this is beginning to change, as illustrated by the work of the World Bank Group (WBG) whose task is to fight poverty worldwide through sustainable solutions. The WBG is now tackling the twin challenge of achieving UHC and reducing/managing climate related risks through the development of financing architectures that ensure joint development initiatives that serve both the health and climate agendas. Soon after the Paris Agreement, the WBG developed a climate

action plan, which defines increased cross-sectoral support and reaffirms commit-ment for a one-third increase in climate financing under World Bank-funded pro-jects; estimated at $16 billion by 2020. Taking this a step further, the Bank has also developed a specific action plan for climate and health, and has conceptualized ways of moving toward climate-smart lending in the health sector while supporting global efforts in achieving UHC. This push to increasing financing in areas related to climate change and health while adopting a UHC lens comes with the purpose of: establishing fair, efficient and sustainable health systems that are also adaptive;

ensuring equity, affordability and quality of health services that are also resilient;

and leveraging cross-sectoral climate-smart interventions to benefit health results and outcomes. This is particularly important in the case of lower-income coun-tries which suffer the most from climate-related economic losses that at times may exceed 10% of their GDP.

UHC is sensitive to spatial and temporal variations in disease risk. For instance, Worrall and colleagues demonstrated that the cost of a malaria case prevented in a low malaria transmission year may be 20 times that of the cost of a case prevented in a high transmission year.³⁶ Improved targeting of health interventions is an emerg-ing priority at a time of increasemerg-ingly scarce resources. Furthermore, threats to health are increasingly understood as threats to societal well-being and security.

1.3.7 Climate shocks and conflict

The global food baskets, which provide cereal staples for the majority of the world’s population are at risk from multiple shocks including climate shocks according to a recent study by Janetos et al. (2017).ⁱⁱⁱ In their analysis, the authors consider the intelligence communities’ failure to recognize the potential impacts of drought and high food prices in Syria immediately preceding the current civil war.³⁷ They note that while some analysts had been warning of the danger of large-scale migration, the broader community:

overlooked the links between infrastructure (the construction of a dam in Turkey to support agricultural self-sufficiency) and an extreme weather event in Syria (a drought that co-occurred with a global food price spike), with what has become a protracted civil war with extensive civilian casualties.

At a more local level, the duration of drought has been shown to increase the likelihood of conflict for politically marginalized and agriculturally dependent groups – especially those residing in countries characterized by very low socioec-onomic development.³⁸

1.3.8 The Global Health Security Agenda

The emergence of a new global health security community initiated by the Global Health Security Agenda (GHSA) in 2014 focused first on pandemic health threats,

but soon acknowledged that there is an inter-connected cascade of health security threat drivers. In addition to pandemic threats these include food insecurity, social unrest, biological, radiological, chemical and multi-hazard threats including cyber threats. This perspective requires a new, integrating lens which brings together the diverse communities that must respond at national and international level to such dangers. Using a whole-of-society approach the full range of threats is presented in Box 1.2. The GHSA offers to bring all of these challenges together at the highest level of government where a cross-sectoral approach to the health and well-being of citizens can be addressed. Accordingly, a high level of coordination across all eight community specialist domains is required to assure human survival and prosperity to meet the Sustainable Development and Global Health Security goals. The USA has been leading the GHSA but this will likely change as a result of funding cuts to the Centers for Disease Control.

Targeting health interventions requires a detailed understanding of the place-based nature of emergent health threats, their potential for rapid spread and the importance of early intervention, which can only be established with pertinent, high quality, information. Thus, achievement of SDGs in general, and the health targets in particular, is increasingly being associated with data-rich, evidence-based approaches. Climate data is identified as one source of necessary information for better management of climate sensitive health outcomes.³⁹